Table 4.
Antioxidant activity of EOs measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH) method and expressed as EC50.
| Essential Oil | EC50 (µL/mL) | AAI |
|---|---|---|
| Bitter orange | N.D. | N.D. |
| Clove | 0.36 ± 0.02 | 59.17 |
| Eucalyptus | N.D. | N.D. |
| Fennel | 90.86 ± 0.14 | 0.23 |
| Lavender | 665.54 ± 0.50 | 0.03 |
| Oregano | 11.58 ± 0.22 | 1.84 |
| Palmarosa | 950.52 ± 0.71 | 0.02 |
| Pepper | 62.10 ± 0.23 | 0.34 |
| Star anise | 500.57 ± 0.33 | 0.04 |
| Tea tree | 54.81 ± 0.24 | 0.39 |
| Turmeric | 24.99 ± 0.44 | 0.85 |
| Chinese yin yang | 5.35 ± 0.13 | 3.98 |
| Japanese yin yang | N.D. | N.D. |
| Ylang ylang | 12.71 ± 0.17 | 1.68 |
AAI = antioxidant activity index; N.D. = antioxidant activity not detected. Values presented as mean ± standard deviation.